I felt more easy to teach LY for teenagers than before.
I encourage them to practise LY to improve their confidence ,courage and creativeness which they need
rather than health which they not concerned.
A fter LY history and basic conceipts I show them some movie clips
Ask them to be a circle form and nobody can run away and do swing laughter first after warming up of ho ho ha ha ha 
one-to-one for play the finger-guessing game and win to laugh(or lose to laugh) 
I found the teenagers like to have a reason to laugh( my son told me that )
I ask one or two student to do example following me and give them some reward in return after exercise..
